I recently installed trial Webuzo on VPS and quite happy using it.
One confusing thing i found which is easily reproducing even in your end-user online demo page. Here are the steps:

1. follow http://demo.webuzo.com/enduser/ (or any installed webuzo instance)
2. Click on Scripts: Javascripts link at the top left navigation and you will see menu with unshown images in at least Chrome, IE9, FF4 (i attached screenshot) and strange menu behavior